Write-once recording medium, recording method, recording apparatus, reproduction method, and reproduction apparatus

ABSTRACT

A write-once recording medium is provided, which comprises a management information area for recording management information for managing a recorded state, and a user data area for recording user data. The user data area is configured to contain at least one recording area. At least one session is configured to contain at least one of the at least one recording area. The management information contains range information indicating a recording range of the at least one recording area and identification information for identifying the recording area located at a boundary of the session.

This application is a continuation of U.S. patent application Ser. No.10/886,830 filed Jul. 7, 2004, now U.S. Pat. No. 7,529,171 and isrelated to (U.S. application Ser. No. 12/408,754) filed on Mar. 23,2009, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a write-once recording mediumcomprising a management information area for recording managementinformation for managing a recorded state and a user data area forrecording user data, and a method and apparatus for recording data ontothe write-once recording medium, and a method and apparatus forreproducing data from the write-once recording medium.

2. Description of the Related Art

Optical discs are information recording media that are compatiblebetween a plurality of apparatuses. Examples of optical discs include,for example, the CD which was originally developed for recording musicand recently are widely used for recording data, DVD which was developedfor recording digital video and are rapidly becoming widespread, andnext-generation optical discs which are currently being developed forrecording high-quality video, such as for high-definition television orthe like.

These optical discs are roughly categorized into three groups in termsof the recording/reproduction method: a read-only type; a write-oncetype; and a rewritable type. Write-once optical discs are made of arecording material, from which recorded data cannot be erased. Data canbe recorded once in the same place on the medium. For example, CD-R andDVD-R are write-once optical discs. Write-once optical discs are alsoreferred to as write-once-many-read optical discs. For rewritableoptical discs, data can be recorded many times in the same place on themedium. For example, CD-RW and DVD-RAM are rewritable optical discs.

Write-once optical discs are not rewritable due to the characteristicsof the recording material. Therefore, it is necessary to manage recordedareas and unrecorded areas. In a CD-R, the recording start position andthe last recorded position of each music composition are managed so asto incrementally record in units of a music composition. The unit of amusic composition is called a track (hereinafter also referred to as a“TRACK” so as to distinguish it from a track indicating a groove). In aCD-R, data is recorded sequentially in units of a track from its innerperiphery to its outer periphery. A plurality of recorded TRACKs aremanaged as a session including a plurality of recorded TRACKs(hereinafter referred to as a “SESSION”). An area for storing managementinformation for managing a recorded state is called a program managementarea (hereinafter also referred to as a “PMA”).

For DVD-R, an RZone (corresponding to a TRACK of CD), a Border(corresponding to a SESSION of CD), and a recording management area(hereinafter also referred to as an “RMA”; corresponding to a PMA of CD)are defined (for example, SFF 8090i standard, “Mt. Fuji Command forMultimedia Devices”, Section 4.16 entitled “Recording for DVD-R media”).

There is a technique for applying a method for managing areas allocatedon DVD-R compatibly to read-only DVD-ROM (for example, JapaneseLaid-Open Publication No. 2001-148166).

In a data structure recorded in an RMA of DVD-R, a recording managementdata (hereinafter also referred to as an “RMD”) is defined.

FIG. 23 shows a field 3 of an RMD. The field 3 of an RMD storesinformation indicating the positions of a maximum of 512 Borders(corresponding to a SESSION of CD).

FIG. 24 shows a field 4 of an RMD. FIG. 25 shows fields 5 to 12 of anRMD. The field 4, and the fields 5 to 12 of an RMD store informationindicating the positions of a maximum of 2302 RZone's (corresponding toa TRACK of CD).

However, in conventional techniques for managing recording areas, thenumber of recording areas to be managed is currently already large. Ifthe conventional techniques are applied without modification to a largercapacity of future media, management information is adversely enlarged.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a write-once recordingmedium is provided, comprising: a management information area forrecording management information for managing a recorded state; and auser data area for recording user data. The user data area is configuredto contain at least one recording area. At least one session isconfigured to contain at least one of the at least one recording area.The management information contains range information indicating arecording range of the at least one recording area and identificationinformation for identifying the recording area located at a boundary ofthe session.

In one embodiment of this invention, the identification information is aflag provided to the recording area. The flag has either a value of “0”or a value of “1”.

In one embodiment of this invention, the flag having a value of “1” isprovided to the recording area located at the beginning of the session.

In one embodiment of this invention, the value of the flag provided tothe recording area contained in a session of the at least one session isinverse to the value of the flag provided to the recording area ofanother session of the at least one session adjacent to that session.

In one embodiment of this invention, a distinct number is provided tothe at least one recording area. The identification information is anarray containing a number provided to the recording area located at thebeginning of the session.

According to another aspect of the present invention, a recording methodfor a write-once recording medium is provided. The medium comprises: amanagement information area for recording management information formanaging a recorded state; and a user data area for recording user data.

The user data area is configured to contain at least one recording area.At least one session is configured to contain at least one of the atleast one recording area. The management information contains rangeinformation indicating a recording range of the at least one recordingarea and identification information for identifying the recording arealocated at a boundary of the session. The method comprises the stepsof:(a) generating the management information; and (b) recording themanagement information into the management information area.

In one embodiment of this invention, the step of (a) comprisesgenerating the management information so that at least one of the atleast one recording area is divided into two recording areas.

In one embodiment of this invention, the step of (a) comprisesgenerating the management information so that recording is disabled.

In one embodiment of this invention, before the step of (a), it isdetermined whether or not the number of the at least one recording areais less than a predetermined value M, where M is an integer of 2 ormore.

In one embodiment of this invention, the step of (a) comprises dividingan outermost recording area of the at least one recording area into twowhere the end of recorded portion of the outermost recording area is aboundary, and generating the management information so that recording isdisabled from the beginning to the end of recorded portion of theoutermost recording area.

In one embodiment of this invention, the step of (a) further comprises,when a boundary of the session is newly added, determining whether ornot a recording area of the at least one recording area containing asector having a maximum sector number has been recorded.

According to another aspect of the present invention, a recordingapparatus for a write-once recording medium is provided. The mediumcomprises: a management information area for recording managementinformation for managing a recorded state; and a user data area forrecording user data. The user data area is configured to contain atleast one recording area. At least one session is configured to containat least one of the at least one recording area. The managementinformation contains range information indicating a recording range ofthe at least one recording area and identification information foridentifying the recording area located at a boundary of the session. Theapparatus comprises: (a) a section for generating the managementinformation; and (b) a section for recording the management informationinto the management information area.

According to another aspect of the present invention, a reproductionmethod for a write-once recording medium is provided. The mediumcomprises: a management information area for recording managementinformation for managing a recorded state; and a user data area forrecording user data. The user data area is configured to contain atleast one recording area. At least one session is configured to containat least one of the at least one recording area. The managementinformation contains range information indicating a recording range ofthe at least one recording area and identification information foridentifying the recording area located at a boundary of the session. Themethod comprises the steps of: (a) reading the management informationfrom the management information area; and (b) recognizing informationregarding the session based on the management information read out.

In one embodiment of this invention, the step of (b) comprises: (b-1)obtaining the total number of the at least one session based on themanagement information read out; (b-2) obtaining a recording area of theat least one recording area located at the beginning of a last sessionof the at least one session; and (b-3) obtaining a session of the atleast one session belonging to a predetermined recording area of the atleast one recording area.

In one embodiment of this invention, the identification information is aflag provided to the at least one recording area. The flag has either avalue of “0” or a value of “1”. The flag having a value of “1” isprovided to a recording area of the at least one recording area locatedat the beginning of each of the at least one session. The step of (b-1)comprises obtaining the total number of the at least one session basedon the flag having a value of “1”. The step of (b-2) comprises obtaininga recording area of the at least one recording area located at thebeginning of a last session of the at least one session based on a lastflag of the flag(s) having a value of “1”. A distinct number is providedto each of the at least one session. The step of (b-3) comprisesobtaining a number provided to a session of the at least one session towhich the predetermined recording area belongs, based on the number ofthe flag(s) having a value of “1” of the flag(s) over the range from arecording area of the at least one recording area located at thebeginning of a leading session of the at least one session to thepredetermined recording area.

In one embodiment of this invention, the identification information is aflag provided to the recording area. The flag has either a value of “0”or a value of “1”. The value of the flag provided to the recording areacontained in a session of the at least one session is inverse to thevalue of the flag provided to the recording area of another session ofthe at least one session adjacent to that session. The step of (b-1)comprises obtaining the total number of the at least one session basedon the number of inversions of the value(s) of the flag(s). The step of(b-2) comprises obtaining a recording area of the at least one recordingarea located at the beginning of a last session of the at least onesession, based on the flag having the last inverted value. A distinctnumber is provided to each of the at least one session. The step of(b-3) comprises obtaining a number provided to a session of the at leastone session to which the predetermined recording area belongs, based onthe number of inversions of the value(s) of the flag(s) over the rangefrom a recording area of the at least one recording area located at thebeginning of a leading session of the at least one session to thepredetermined recording area.

In one embodiment of this invention, a distinct number is provided toeach of the at least one recording area. The identification informationis an array of a number(s) provided to a recording area of the at leastone recording area located at the beginning of each of the at least onesession. The step of (b-1) comprises obtaining the total number of thenumber(s) contained in the array. The step of (b-2) comprises obtaininga recording area of the at least one recording area located at thebeginning of a last session, based on a last number of the number(s)contained in the array. A distinct number is provided to each of the atleast one session. The step of (b-3) comprises obtaining a numberprovided to a session of the at least one session to which thepredetermined recording area belongs, based on the number of number(s)smaller than the number provided to the predetermined recording areacontained in the array.

According to another aspect of the present invention, a reproductionapparatus for a write-once recording medium is provided. The mediumcomprises: a management information area for recording managementinformation for managing a recorded state; and a user data area forrecording user data.

The user data area is configured to contain at least one recording area.At least one session is configured to contain at least one of the atleast one recording area. The management information contains rangeinformation indicating a recording range of the at least one recordingarea and identification information for identifying the recording arealocated at a boundary of the session. The apparatus comprises: (a) asection for reading out the management information from the managementinformation area; and (b) a section for recognizing informationregarding the at least one session based on the management informationread out.

Thus, according to the write-once recording medium of the presentinvention, one session is comprised of at least one of the at least onerecording area, and management information contains identificationinformation for identifying a recording area located at a boundary of asession. Therefore, a boundary of a session can be identified based ononly a recording area located at the beginning of a session. As aresult, the size of information for identifying a boundary of a sessioncan be reduced.

In addition, according to the write-once recording medium of the presentinvention, management information can contain information indicating arecording area located at the beginning of a session, thereby making itpossible to reduce the size of the management information. Therefore, ifthe size of an area for incrementally writing management information isthe same, the number of times with which the user can incrementallywrite management information can be increased. If the number of timeswith which the user can incrementally write management information isthe same, the size of an area for incrementally writing managementinformation can be reduced. As a result, a capacity for recording userdata can be increased.

According to the recording method and the recording apparatus of thepresent invention, it is possible to record/reproduce managementinformation onto/from the write-once recording medium of the presentinvention. Since management information can be recorded onto thewrite-once recording medium having only a small size of area forrecording management information, the time required for searching forthe latest management information can be reduced. As a result, the timerequired from when the user loads the write-once recording medium intoan apparatus to when a user data area of the write-once recording mediumis ready to access, can be reduced.

Thus, the invention described herein makes possible the advantages ofproviding a write-once recording medium having a smaller size ofmanagement information and a larger capacity; a method and apparatus forrecording data to the write-once recording medium; and a method andapparatus for reproducing data from the write-once recording medium.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a structure of an optical disc 1 accordingto an embodiment of the present invention.

FIG. 2 is a diagram showing a data structure of management information 8according to an embodiment of the present invention.

FIG. 3 is a diagram showing a transition from an unrecorded area, arecorded area, to a 0-padding recorded area on the optical disc 1.

FIG. 4 is a diagram showing a transition of the contents of entry numberarray 10 and recording area entry 11.

FIG. 5 is a diagram showing a transition from an unrecorded area, arecorded area, to a 0-padding recorded area on the optical disc 1.

FIG. 6 is a diagram showing a transition of the contents of the entrynumber array 10 and the recording area entry 11.

FIG. 7 is a diagram showing another exemplary data structure of themanagement information 8 according to an embodiment of the presentinvention.

FIG. 8 is a diagram showing a transition of the contents of the entrynumber array 10 and the recording area entry 11.

FIG. 9 is a diagram showing still another exemplary data structure ofthe management information 8 according to an embodiment of the presentinvention.

FIG. 10 is a diagram showing a transition of the contents of the entrynumber array 10 and the recording area entry 11.

FIG. 11 is a diagram showing an exemplary structure of an optical discapparatus 100 according to an embodiment of the present invention.

FIG. 12 is a flowchart showing a recording procedure according to anembodiment of the present invention.

FIG. 13 is a flowchart showing details of a procedure for readingmanagement information.

FIG. 14 is a flowchart showing details of a procedure for writingmanagement information.

FIG. 15 is a flowchart showing details of a procedure for adding arecording area.

FIG. 16 is a flowchart showing details of a procedure for closing arecording area.

FIG. 17 is a flowchart showing details of a procedure for closing asession.

FIG. 18 is a diagram showing an exemplary structure of an optical discapparatus 200 according to an embodiment of the present invention.

FIG. 19 is a flowchart showing a reproduction procedure according to anembodiment of the present invention.

FIG. 20 is a flowchart showing an exemplary calculation procedureaccording to an embodiment of the present invention.

FIG. 21 is a flowchart showing another exemplary calculation procedureaccording to an embodiment of the present invention.

FIG. 22 is a flowchart showing still another exemplary calculationprocedure according to an embodiment of the present invention.

FIG. 23 is a diagram showing a field 3 of an RMD.

FIG. 24 is a diagram showing a field 4 of an RMD.

FIG. 25 is a diagram showing fields 5 to 12 of an RMD.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described inthe following sections (1. Write-once recording medium), (2-1. Recordingapparatus), (2-2. Recording method), (3-1. Reproduction apparatus), and(3-2. Reproduction method) with reference to the accompanying drawings.

1. Write-Once Recording Medium

FIG. 1 shows a structure of an optical disc 1 according to an embodimentof the present invention.

The optical disc 1 is in the shape of a disc. In the optical disc 1, aspiral track groove 2 is provided. In the track groove 2, a plurality ofblocks 3 are provided. The block 3 is a unit for error correction aswell as a unit for recording/reproduction of information.

The optical disc 1 has a lead-in area 4, a lead-out area 6, and a dataarea 5 for recording user data. The data area 5 is configured to have atleast one recording area. Recording/reproduction of data is performedwith respect to the data area 5.

The lead-in area 4 and the lead-out area 6 serve as margins which allowsan optical head (not shown) to follow the track groove 2 when theoptical head accesses an end of the data area 5 and overruns the dataarea 5.

The lead-in area 4 has a management information area 7 for recordingmanagement information 8 for managing a recorded state. A plurality ofpieces of management information 8 may be, for example, used to manage arecorded area and an unrecorded area. A plurality of pieces ofmanagement information 8 are each recorded in at least one block 3.

FIG. 2 shows a data structure of the management information 8 accordingto an embodiment of the present invention.

Each management information 8 contains a management information header 9for identifying one of a plurality of pieces of management information8, an entry number array 10 of incrementally writable recording areas,and a plurality of recording area entries 11. The entry number array 10is information for identify a recording area, in which data can berecorded.

Each recording area entry 11 contains identification information foridentifying a recording area located at a boundary of a session, andrange information indicating a recording range of at least one recordingarea.

The identification information is, for example, a session start flag 12which indicates which of the recording area entries 11 is a boundary(e.g., the beginning or the like) of a session. A session start flag 12is given to at least one recording area, having a value of “0” or “1”.For example, a session start flag 12 having a value of “1” is given to arecording area located at a boundary (e.g., the beginning or the like)of a session. In each recording area entry 11, a number (1 to N)following # indicates an entry number. Thus, at least one recordingareas are each given distinct entry numbers N is an integer of 1 ormore. One session is comprised of at least one of the recording areas.

Range information contains, for example, a start position 13 and a lastrecorded position 14 of a recording area.

Thus, the recording area of the present invention corresponds to theTRACK of CD-R and the RZone of DVD-R. The session of the presentinvention corresponds to the SESSION of CD-R and the Border of DVD-R.The session of the present invention contains none of the lead-in area4, the lead-out area 6, a Border-In area (not shown), and a Border-Outarea (not shown) (see FIG. 3 described below). Therefore, the entrynumber array 10 corresponds to information from Byte 0 to Byte 5 (FIG.24). The recording area entries 11 correspond to information obtained byadding the session start flag 12 to information of Byte 16 andthereafter (FIG. 24) and from Byte 0 to Byte 2047 (FIG. 25).

In DVD-R (a conventional write-once medium), 2048 bytes of managementinformation is required for management of a maximum of 512 Borders(corresponding to a session of the present invention) (FIG. 23). In thepresent invention, one bit of the recording area entry 11 is allocatedto the session start flag 12, thereby making it possible to manage asession.

Hereinafter, session management according to an embodiment of thepresent invention will be described below.

FIG. 3 shows a transition from an unrecorded area, a recorded area, to a0-padding recorded area on the optical disc 1. In FIG. 3, the unrecordedarea of the optical disc 1 has a white background color, the recordedarea has a black background color, and the 0-padding recorded area ishatched.

FIG. 4 shows a transition of the contents of the entry number array 10and the recording area entry 11.

Portion (a) of FIG. 3 and portion (a) of FIG. 4 show concurrent states.Portion (b) of FIG. 3 and portion (b) of FIG. 4 show concurrent states.Similarly, portion (c) to portion (g) of FIG. 3 and correspondingportion (c) to portion (g) of FIG. 4 show concurrent states.

Portion (a) of FIG. 3 and portion (a) of FIG. 4 show an initial state ofthe optical disc 1.

The data area 5 is configured to contain a recording area #1. Thesession #1 contains a recording area #1. No information has beenrecorded in the recording area #1.

In the entry number array 10, a number “1” is registered which indicatesthat the recording area #1 is incrementally writable. In another portionof the entry number array 10, a number “0” is registered which indicatesthat there is no incrementally writable recording area other than therecording area #1.

In the recording area entry #1, the session start flag 12 is set to be avalue of “1”, the start position 13 of the recording area #1 is set tobe a position P1, and the last recorded position 14 of the recordingarea #1 is set to be a value of “0” which indicates an unrecorded stateThe position P1 indicates the beginning of the data area 5. In arecording area entry #2 and a recording area entry #3, the session startflag 12, the start position 13, and the last recorded position 14 of therecording area #2 and the recording area #3 are set to be “0” so as toindicate that there is no corresponding recording area.

Portions (b) of FIGS. 3 and 4 show a state of the data area after aRESERVE TRACK command has been received from a higher-level controlapparatus. The RESERVE TRACK command indicates reservation of arecording area. Note that commands from a higher-level control apparatus(for example, a RESERVE TRACK command) are defined in a general hostcommand standard (see, for example, see SFF 8090i standard, “Mt. FujiCommand for Multimedia Devices”, Section 4.16 entitled “Recording forDVD-R media”).

The management information 8 is generated (or changed) to indicate thatthe recording area #1 from the position P1 to the end of the data area 5is divided into a recording area #1 from the position P1 to a positionP3 and a recording area #2 from the position P3 to the end of the dataarea 5. The recording area #1 and the recording area #2 belong to thesession #1. P3 is a value obtained by adding a size designated by theRESERVE TRACK command to P1. In the data area 5, there is no recordedarea.

In the entry number array 10, a number “1” indicating that the recordingarea #1 is incrementally writable and a number “2” indicating that therecording area #2 is incrementally writable, are registered. In theentry number array 10, entry numbers are sorted in the descending order.Note that the sorting order of the entry number array 10 is not limitedto the descending order, and the sorting may be performed in theascending order or may not be performed.

In the recording area entry #2, the session start flag 12 of therecording area #2 is set to be a value of “0”, and the start position 13of the recording area #2 is set to be the position P3.

Hereinafter, the contents of management information which have no changeare not described for the sake of brevity.

Portions (c) of FIGS. 3 and 4 show a state of the data area 5 after theRESERVE TRACK command has been received from the higher-level controlapparatus.

The management information 8 is generated (or changed) to indicate thatthe recording area #2 from the position P3 to the end of the data area 5is divided into a recording area #2 from the position P3 to a positionP5 and a recording area #3 from the position P5 to the end of the dataarea 5. The recording area #1 is not changed. The recording area #1, therecording area #2, and the recording area #3 belong to the session #1.P5 has a value obtained by adding a size designated by the RESERVE TRACKcommand to P3. In the data area 5, there is no recorded area.

In the entry number array 10, in order to indicate that the recordingarea #3 has been added, a number “3” is added which indicates that therecording area #3 is incrementally writable.

In the recording area entry #3, the session start flag 12 of therecording area #3 is set to be a value of “0”, and the start position 13of the recording area #3 is set to be the position P5.

Portions (d) of FIGS. 3 and 4 show a state of the data area 5 after aWRITE command has been received from a higher-level control apparatus.The WRITE command indicates recording of data into the recording area #1and the recording area #2.

By recording data into the recording area #1, the last recorded position14 of the recording area #1 is changed into a position (P2−1). Byrecording data into the recording area #2, the last recorded position 14of the recording area #2 is changed into a position (P4−1).

Note that since the last recorded position 14 is defined as the positionof a recorded block 3, the last recorded position 14 is a positionobtained by subtracting 1 from the position P2 or a position bysubtracting 1 from the position P4. However, for example, if the lastrecorded position 14 is defined as the position of the next recordedblock 3, it is not necessary to subtract 1. For the sake of convenience,hereinafter, session management according to an embodiment of thepresent invention will be descried below, while the last recordedposition 14 is defined as the position of a recorded block 3.

In the recording area entry #1, the last recorded position 14 of therecording area #1 is set to be the position (P2−1). In the recordingarea entry #2, the last recorded position 14 of the recording area #2 isset to be the position (P4−1).

Portions (e) of FIGS. 3 and 4 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated TRACK (the recording area#1 is designated) has been received from a higher-level controlapparatus. The CLOSE TRACK/SESSION command for a designated TRACK (therecording area #1 is designated) indicates that it is no longernecessary to record further information into the recording area #1.

0-padding data is recorded into an unrecorded area of the recording area#1 (an area from the position P2 to the position P3), and the recordingarea #1 becomes closed. In order to indicate that the recording area #1is not incrementally writable, the number “1” is removed from the entrynumber array 10.

Portions (f) of FIGS. 3 and 4 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated TRACK (the recording area#2 is designated) has been received from a higher-level controlapparatus. The CLOSE TRACK/SESSION command for a designated TRACK (therecording area #2 is designated) indicates that it is no longernecessary to record further information into the recording area #2.

0-padding data is recorded into an unrecorded area of the recording area#2 (an area from the position P4 to the position P5), and the recordingarea #2 becomes closed. In order to indicate that the recording area #2is not incrementally writable, the number “2” is removed from the entrynumber array 10.

Portions (g) of FIGS. 3 and 4 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated a SESSION (the session #1is designated) has been received from a higher-level control apparatus.

The closed recording area #1 and the closed recording area #2 belong tothe session #1, while the recording area #3 having no recordedinformation belongs to the session #2.

In the recording area entry #3, the session start flag 12 is set to be avalue of “1”. Thus, the session start flag 12 is given to a plurality ofrecording areas, which has any one of a value of “0” and a value of “1”.The session start flag 12 having a value of “1” is given to a recordingarea located at the beginning of a session.

FIG. 5 shows a transition from an unrecorded area, a recorded area, to a0-padding recorded area on the optical disc 1. In FIG. 5, the unrecordedarea of the optical disc 1 has a white background color, the recordedarea has a black background color, and the 0-padding recorded area ishatched.

FIG. 6 shows a transition of the contents of the entry number array 10and the recording area entry 11.

FIG. 5 shows what follows FIG. 3. FIG. 6 shows what follows FIG. 4.

Portions (g′) of FIGS. 5 and 6 show concurrent states. Portion (h) ofFIGS. 5 and 6 show concurrent states. Similarly, portions (i) to (l) ofFIG. 5 and corresponding portions (i) to (l) of FIG. 6 show concurrentstates. Portion (g′) of FIG. 5 shows the same state as that of portion(g) of FIG. 3. Portion (g′) of FIG. 6 shows the same state as that ofportion (g) of FIG. 4. Therefore, Portions (g′) of FIGS. 5 and 6 are notdescribed.

Portions (h) of FIGS. 5 and 6 show a state of the data area 5 after aRESERVE TRACK command has been received from a higher-level controlapparatus.

The management information 8 is generated (or changed) to indicate thatthe recording area #3 from the position P5 to the end of the data area 5is divided into a recording area. #3 from the position P5 to a positionP6 and a recording area #4 from the position P6 to the end of the dataarea 5. The recording area #1 and the recording area #2 are not changed.The recording area #1 and the recording area #2 belong to the session#1. The recording area #3 and the recording area #4 belong to a session#2. P6 is a value obtained by adding a size designated by the RESERVETRACK command to P5.

In the entry number array 10, a number 4 indicating that the recordingarea #4 is incrementally writable, is registered to indicate that therecording area #4 has been added.

In the recording area entry #4, the session start flag 12 of therecording area #4 is set to have a value of “0”, while the startposition 13 of the recording area #4 is set to be the position P6.

Portions (i) of FIGS. 5 and 6 show a state of the data area 5 after aWRITE command has been received from a higher-level control apparatus.The WRITE command indicates recording of data into the recording area #3and the recording area #4.

By recording data into the recording area #3, the last recorded position14 of the recording area #3 is changed into a position (P7−1). Byrecording data into the recording area #4, the last recorded position 14of the recording area #4 is changed into a position (P8−1).

In the recording area entry #3, the last recorded position 14 of therecording area #3 is set to be the position (P7−1). In the recordingarea entry #4, the last recorded position 14 of the recording area #4 isset to be the position (P8−1).

Portions (j) of FIGS. 5 and 6 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated TRACK (the recording area#3 is designated) has been received from a higher-level controlapparatus. The CLOSE TRACK/SESSION command for a designated TRACK (therecording area #3 is designated) indicates that it is no longernecessary to record further information into the recording area #3.

0-padding data is recorded into an unrecorded area of the recording area#3 (an area from the position P7 to the position P6), and the recordingarea #3 becomes closed. In order to indicate that the recording area #3is not incrementally writable, the number “3” is removed from the entrynumber array 10.

Portions (k) of FIGS. 5 and 6 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated TRACK (the recording area#4 is designated) has been received from a higher-level controlapparatus. The CLOSE TRACK/SESSION command for a designated TRACK (therecording area #4 is designated) indicates that it is no longernecessary to record further information into the recording area #4.

The recording area #4 from the position P6 to the end of the data area 5is an outermost recording area. Therefore, the management information 8is generated (or changed) to indicate that the recording area #4 fromthe position P6 to the end of the data area 5 is divided into arecording area #4 from the position P6 to a position P8 and a recordingarea #5 from the position P8 to the end of the data area 5. Therecording area #4 becomes closed. The recording area #1, the recordingarea #2, and the recording area #3 are not changed.

In order to indicate that the recording area #4 is not incrementallywritable, the number “4” is removed from the entry number array 10. Inorder to indicate that the recording area #5 has been added, a number“5” is added into the entry number array 10, which indicates that therecording area #5 is incrementally writable.

Portions (l) of FIGS. 5 and 6 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated SESSION (the session #2 isdesignated) has been received from a higher-level control apparatus.

The closed recording area #3 and the closed recording area #4 belong tothe session #2, while the recording area #5 having no recordedinformation belongs to the session #3.

In the recording area entry #5, the session start flag 12 is set to be avalue of “1”.

Thereafter, steps similar to those which are described with reference toportions (g′) to (l) of FIGS. 5 and 6 are repeatedly performed until allof desired user data are recorded.

A READ DISC INFORMATION command and a READ TRACK INFORMATION command arecommands which are issued from a higher-level control apparatus toinquire the state of a SESSION and the state of a TRACK, respectively(for example, SFF 8090i standard, “Mt. Fuji Command for MultimediaDevices”, Section 4.16 entitled “Recording for DVD-R media”). To providecompatibility with conventional CD-R and DVD-R, it is reported inresponse to these commands that a TRACK is present in each of aplurality of recorded areas.

Specifically, in the case of the state shown in portions (h) of FIGS. 5and 6, it is reported that SESSION #1 has TRACK #1 and TRACK #2 andSESSION #2 has TRACK #3 and TRACK #4.

In the case of the state shown in portions (l) of FIGS. 5 and 6, it isreported that SESSION #1 has TRACK #1 and TRACK #2, SESSION #2 has TRACK#3 and TRACK #4, and SESSION #3 has TRACK #5.

By managing the transitions shown in FIGS. 3, 4, 5 and 6, the end usercan record user data using a writing software called CD Burning (forexample, an application corresponding to Disc-At-Once, Track-At-Once,and Session-At-Once recording operations).

In this embodiment of the present invention, 0-padding data is recordedinto an unrecorded area of a recording area in response to a CLOSETRACK/SESSION command for a designated TRACK. The 0-padding data may beany data. In addition, for example, management information may be causedto indicate that any data is recorded in an unrecorded area of arecording area, while, in fact, no data is recorded in an unrecordedarea of a recording area.

The order of the session start flag 12, the start position 13, and thelast recorded position 14 arranged in the recording area entry 11 is notlimited to this order.

As long as it can be determined whether or not a predetermined recordingarea is located at the beginning of a session, the last recordedposition of a recording area can be referenced instead of the startposition 13 of a recording area in order to recognize the beginning of asession. The size of a recording area may be referenced instead of thestart position or the last recorded position of a recording area.

The management information header 9 may contain, for example, the numberof recording area entries registered in the entry number array 10 (i.e.,the total number of incrementally writable recording areas), the numberof entries registered in the recording area entry 11 (i.e., the totalnumber of recording areas), or the number of session start flags 12having a value of “1” (i.e., the total number of sessions).

Thus, according to the write-once recording medium of the presentinvention, one session is comprised of at least one of the at least onerecording area, and management information contains identificationinformation for identifying a recording area located at a boundary of asession. Therefore, a boundary of a session can be identified based ononly a recording area located at the beginning of a session. As aresult, the size of information for identifying a boundary of a sessioncan be reduced.

In addition, according to the write-once recording medium of the presentinvention, management information can contain information indicating arecording area located at the beginning of a session, thereby making itpossible to reduce the size of the management information. Therefore, ifthe size of an area for incrementally writing management information isthe same, the number of times with which the user can incrementallywrite management information can be increased. If the number of timeswith which the user can incrementally write management information isthe same, the size of an area for incrementally writing managementinformation can be reduced. As a result, a capacity for recording userdata can be increased.

The write-once recording medium according to the embodiment of thepresent invention has heretofore been described with reference to FIGS.2 to 6.

For example, in the embodiment of FIGS. 2 to 6, the managementinformation area 7 corresponds to a “management information area forrecording management information for managing a recorded state”. Thedata area 5 corresponds to a “user data area for recording user data,which is configured to contain at least one recording area”. Each of thesessions #1 to #3 corresponds to a “session which is comprised of atleast one of the at least one recording area”. The session start flag 12corresponds to “identification information for identifying a recordingarea located at a boundary of a session”. Information indicating thestart position 13 of a recording area and information indicating thelast recorded position 14 of a recording area corresponds to “rangeinformation indicating a recording range of at least one recordingarea”.

However, the write-once recording medium of the present invention is notlimited to the embodiment of FIG. 2 to 6. As long as the write-oncerecording medium has the above-described “management information areafor recording management information for managing a recorded state”,“user data area for recording user data, which is configured to containat least one recording area”, and “session which is comprised of atleast one of the at least one recording area”, and information to berecorded onto the write-once recording medium is the above-described“identification information for identifying a recording area located ata boundary of a session” and “range information indicating a recordingrange of at least one recording area”, the write-once recording mediumcan have any structure.

Identification information may be, for example, a session toggle flag(see FIG. 7). Alternatively, identification information may be an entrynumber array of a recording area at the beginning of a session (see FIG.9).

FIG. 7 shows another exemplary data structure of the managementinformation 8 according to an embodiment of the present invention. InFIG. 7, information which is the same as information contained in themanagement information 8 of FIG. 2 is indicated by the same referencenumeral, and its description is omitted.

A difference between the management information 8 of FIG. 2 and themanagement information 8 of FIG. 7, is that the session start flag 12contained in the management information 8 of FIG. 2 is replaced with thesession toggle flag 15 contained in the management information 8 of FIG.7. The session toggle flag 15 is provided to at least one recordingarea, which has any one of a value of “0” and a value of “1”. The valueof the session toggle flag 15 provided to a recording area contained ina session is inverse to the value of the session toggle flag 15 providedto a recording area contained in a session adjacent to that session.

FIG. 8 shows a transition of the contents of the entry number array 10and the recording area entry 11. Portions (l) of FIGS. 5 and 8 show aconcurrent state.

Portions (l) of FIGS. 5 and 8 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated SESSION (the session #2 isdesignated) has been received from a higher-level control apparatus.

A closed recording area #1 and a closed recording area #2 belong to asession #1. A closed recording area #3 and a closed recording area #4belong to the session #2. A recording area #5 in which no informationhas been recorded belongs to a session #3. The recording area #5 is theonly incrementally writable recording area.

In the recording area entry #1 and the recording area entry #2, thesession toggle flag 15 is set to have a value of “1”. In the recordingarea entry #3 and the recording area entry #4, the session toggle flag15 is set to have a value of “0”. In the recording area entry #5, thesession toggle flag 15 is set to have a value of “1”.

The initial value of the session toggle flag 15 is not limited to avalue of “1”. When the initial value of the session toggle flag 15 isset to be a value of “0”, the session toggle flag 15 is set to have avalue of “0” in the recording area entry #1 and the recording area entry#2, the session toggle flag 15 is set to have a value of “1” in therecording area entry #3 and the recording area entry #4, and the sessiontoggle flag 15 is set to have a value of “0” in the recording area entry#5.

Thus, according to the above-described exemplary write-once recordingmedium of the present invention, by containing, in the managementinformation, information indicating a recording area located at thebeginning of a session, the quantity of management information can bereduced. Therefore, if the size of an area for incrementally writingmanagement information is the same, the number of times with which theuser can incrementally write management information can be increased. Ifthe number of times with which the user can incrementally writemanagement information is the same, the size of an area forincrementally writing management information can be reduced. As aresult, a capacity for recording user data can be increased.

FIG. 9 shows still another exemplary data structure of the managementinformation 8 according to an embodiment of the present invention. InFIG. 9, information which is the same as information contained in themanagement information 8 of FIG. 2 is indicated by the same referencenumeral, and its description is omitted.

A difference between the management information 8 of FIG. 2 and themanagement information 8 of FIG. 9, is that the session start flag 12contained in the management information 8 of FIG. 2 is replaced with anentry number array 16 of a recording area at the beginning of a sessioncontained in the management information 8 of FIG. 9. The entry numberarray 16 is comprised of entry numbers of recording areas located at thebeginnings of sessions. For example, in the entry number array 16, thefirst number is an entry number (i.e., a number “1”) of a recording area#1 located at the beginning of a session #1, the second number is anentry number (i.e., a number “3”) of a recording area #3 located at thebeginning of a session #2, . . . . The entry numbers are listed in theascending order. Thus, in the entry number array 16, the entry number ofa recording area located at the beginning of each session is stored.When a session is not present, a number “0” is stored.

FIG. 10 shows a transition of the contents of the entry number array 10and the recording area entry 11. Portions (l) of FIGS. 5 and 10 show aconcurrent state.

Portions (l) of FIGS. 5 and 10 show a state of the data area 5 after aCLOSE TRACK/SESSION command for a designated SESSION (the session #2 isdesignated) has been received from a higher-level control apparatus.

A closed recording area #1 and a closed recording area #2 belong to asession #1. A closed recording area #3 and a closed recording area #4belong to the session #2. A recording area #5 in which no informationhas been recorded belongs to a session #3. The recording area #5 is theonly incrementally writable recording area.

Therefore, the entry number array 16 contains the entry number “1” ofthe recording area #1, the entry number “3” of the recording area #3,and the entry number “5” of the recording area #5, and the number “0”.

Thus, according to the above-described exemplary write-once recordingmedium of the present invention, by containing, in the managementinformation, information indicating a recording area located at thebeginning of a session, the quantity of management information can bereduced. Therefore, if the size of an area for incrementally writingmanagement information is the same, the number of times with which theuser can incrementally write management information can be increased. Ifthe number of times with which the user can incrementally writemanagement information is the same, the size of an area forincrementally writing management information can be reduced. As aresult, a capacity for recording user data can be increased.

For example, conventionally, 4 bytes are required to indicate a boundaryof a session. In the above-described exemplary write-once recordingmedium of the present invention, only 1 or 2 bytes are required toindicate a boundary of a session.

According to the write-once recording medium of the present invention ofFIGS. 9 and 10, it is simple to calculate the total number of sessions,so that a session number to which each recording area belongs can bequickly calculated, as compared to the write-once recording medium ofthe present invention of FIGS. 3 to 6. As a result, a READ DISCINFORMATION command and a READ TRACK INFORMATION command (for example,SFF 8090i standard, “Mt. Fuji Command for Multimedia Devices”, Section4.16 entitled “Recording for DVD-R media) can be processed with highspeed.

2-1. Recording Apparatus

Hereinafter, a recording apparatus according to an embodiment of thepresent invention will be described with reference to the accompanyingdrawings.

FIG. 11 shows an exemplary structure of an optical disc apparatus 100according to an embodiment of the present invention.

The optical disc apparatus 100 serves as a recording apparatus accordingto an embodiment of the present invention, when recording information.

The optical disc apparatus 100 is connected to an I/O bus 170. The I/Obus 170 is connected to a higher-level control apparatus (not shown).The higher-level control apparatus is typically a host computer.

The optical disc apparatus 100 is configured to load an optical disc 1thereinto. The optical disc apparatus 100 comprises a command processingsection 110 for processing a command from a higher-level controlapparatus, a recording control section 120 for controlling recording ofthe optical disc 1, a reproduction control section 130 for controllingreproduction of the optical disc 1, a management information storingbuffer 140 for storing management information 8 (FIG. 1), a data buffer150 for temporarily storing recording data, and a recording managementprocessing section 160 for processing management information 8.

The recording management processing section 160 comprises a managementinformation reading section 161, a management information writingsection 163 for writing management information 8, stored in themanagement information storing buffer 140, into a management informationarea 7 (FIG. 1), a management information updating section 162 forupdating management information 8, stored in the management informationstoring buffer 140, in accordance with a command from a higher-levelcontrol apparatus, and a management information position memory 164 forstoring the position of the latest management information 8.

The management information reading section 161 searches for managementinformation 8 which was last recorded in the pieces of managementinformation 8 recorded in the management information area 7. Themanagement information 8 last recorded in the management informationarea 7 is read out into the management information storing buffer 140.

2-2. Recording Method

Hereinafter, a recording method according to an embodiment of thepresent invention will be described with reference to the accompanyingdrawings.

FIG. 12 shows a recording procedure according to an embodiment of thepresent invention.

The recording procedure is performed by the recording managementprocessing section 160. The recording management processing section 160performs steps 201 to 208. The management information reading section161 performs reading of management information (step 201). Themanagement information writing section 163 performs writing ofmanagement information (step 207). The management information updatingsection 162 performs the remainder of the recording procedure (steps 202to 206 and step 208).

Hereinafter, the recording procedure of the embodiment of the presentinvention will be described with reference to FIGS. 11 and 12 step bystep. Hereinafter, for example, a procedure for recording managementinformation 8 containing a session start flag and the like onto awrite-once recording medium will be described.

Step 201: when the optical disc 1 is loaded in the optical discapparatus 100, the management information reading section 161 reads thelatest management information 8, and stores the read latest managementinformation 8 into the management information storing buffer 140.

Note that when the latest management information 8 is read out in step201, it may be determined whether or not the number of recording areasis less than a predetermined value of M, where M is an integer of 2 ormore.

Step 202: the optical disc apparatus 100 is ready to receive commandsrelating to the optical disc 1 from a higher-level control apparatusuntil the optical disc 1 is ejected or the power source is turned off.

When a RESERVE TRACK command is issued to the optical disc 1, theprocess goes to step 203. When a CLOSE TRACK/SESSION command is issuedto the optical disc 1, the process goes to step 204. When a WRITEcommand is issued to the optical disc 1, the process goes to step 208.

The RESERVE TRACK command is a command from a higher-level controlapparatus, which requests reservation of a recording area. The CLOSETRACK/SESSION command is a command from a higher-level controlapparatus, which requests closure of a recording area. The WRITE commandis a command from a higher-level control apparatus, which requestsrecording of data.

Step 203: when the RESERVE TRACK command is received, managementinformation 8 stored in the management information storing buffer 140 isgenerated (or changed) so as to add a recording area.

For example, referring to portions (h) of FIGS. 5 and 6, managementinformation 8 is generated (or changed) to indicate that the recordingarea #3 from the position P5 to the end of the data area 5 is dividedinto a recording area #3 from the position P5 to a position P6 and arecording area #4 from the position P6 to the end of the data area 5. Inthe entry number array 10, a number “4” indicating that the recordingarea #4 is incrementally writable, is registered to indicate that therecording area #4 has been added. In the recording area entry #4, thesession start flag 12 of the recording area #4 is set to have a value of“0”, while the start position 13 of the recording area #4 is set to bethe position P6.

After generation (or change), the process goes to step 207.

Step 204: when the CLOSE TRACK/SESSION command is received, it isdetermined whether a subject to be closed is a TRACK or a SESSION. Whenit is determined that the subject to be closed is a TRACK, the processgoes to step 205. When it is determined that the subject to be closed isa SESSION, the process goes to step 206.

Step 205: management information 8 stored in the management informationstoring buffer 140 is generated (or changed) to close a recording area(TRACK).

For example, referring to portions (j) of FIGS. 5 and 6, 0-padding datais recorded into an unrecorded area of the recording area #3 (an areafrom the position P7 to the position P6), and the recording area #3becomes closed. In order to indicate that the recording area #3 is notincrementally writable, the number “3” is removed from the entry numberarray 10.

After generation (or change), the process goes to step 207.

Step 206: management information 8 stored in the management informationstoring buffer 140 is generated (or changed) so as to close a recordingarea belonging to an outermost session.

For example, referring to portions (l) of FIGS. 5 and 6, the closedrecording area #3 and the closed recording area #4 belong to the session#2, while the recording area #5 having no recorded information belongsto the session #3. In the recording area entry #5, the session startflag 12 is set to be a value of “1”.

After generation (or change), the process goes to step 207.

Step 207: when the management information 8 stored in the managementinformation storing buffer 140 is updated, the latest managementinformation 8 is incrementally written into an incrementally writablearea in the management information area 7.

Step 208: when the WRITE command is received, it is determined whatincrementally writable position matches a designated recording startposition, and transferred data is recorded onto the optical disc 1. Theincrementally writable position can be obtained based on the lastrecorded position 14 of the recording area entry 11 registered in theentry number array 10. The value of the last recorded position 14 of themanagement information 8 stored in the management information storingbuffer 140 is generated (or changed) based on the recorded position.

For example, referring to portions (i) of FIGS. 5 and 6, by recordingdata into the recording area #3, the last recorded position 14 of therecording area #3 is changed into a position (P7−1). By recording datainto the recording area #4, the last recorded position 14 of therecording area #4 is changed into a position (P8−1).

Generally, when a position is indicated by a sector number, a valueindicating an incrementally writable position is obtained by adding 1 toa value indicating the last recorded position 14. Note that when thelast recorded position 14 is not registered (value: 0), a valueindicating an incrementally writable position is the same as a valueindicating the start position 13 of a recording area.

When an ECC (error correction code) is comprised of 16 sectors as inDVD, an actual incrementally writable position is a multiple of 16.Therefore, although the four fundamental operations of arithmetic arerequired to some extent to obtain an incrementally writable position, anincrementally writable position can be obtained based on the lastrecorded position 14 or the start position 13.

FIG. 13 shows a procedure for reading management information.

Hereinafter, a procedure for reading management information will bedescribed step by step in detail with reference to FIGS. 11 and 13 (forstep 201, see FIG. 12).

Step 301: the reproduction control section 130 searches for the positionof last recorded management information 8 in the management informationarea 7. Position information indicating the position is stored in themanagement information position memory 164.

Step 302: the reproduction control section 130 references the positionalinformation stored in the management information position memory 164,reproduces the management information 8, and stores the reproducedmanagement information 8 into the management information storing buffer140. When no management information 8 has been recorded in themanagement information area 7 (for example, a brand-new optical disc 1is loaded in the optical disc apparatus 100), the management information8 is initialized (portion (a) of FIG. 4).

Step 303: the reproduction control section 130 searches for the end of arecorded area from the last recorded position 14 as a starting point,obtains an actual last recorded position 14, and updates managementinformation 8 stored in the management information storing buffer 140based on information indicating the actual last recorded position 14.Thereafter, the process is ended.

The last recorded position 14 of each recording area reproduced from themanagement information 8 may be different from the actual last recordedposition, i.e., includes error to some extent. This is because when thelast recorded position 14 of management information 8 is updated everytime the WRITE command is received, a very large number of managementinformation areas 7 are required. For this reason, it is assumed thatmanagement information 8 is incrementally written into the managementinformation area 7 only when a recording area is added or closed (FIG.12). Therefore, the reproduction control section 130 obtains an actuallast recorded position 14 by searching for the end of a recorded areausing the last recorded position 14 as a starting point.

Step 303 may be omitted if the latest contents of the managementinformation storing buffer 140 can be guaranteed to be incorporated intomanagement information 8 of a management information area 7 when theoptical disc 1 is ejected, or the optical disc apparatus 100 is turnedoff, assuming that the optical disc apparatus 100 has a back-up powersource.

FIG. 14 shows details of a procedure for writing management information.

Hereinafter, a procedure for writing management information will bedescribed in detail with reference to FIGS. 11 and 14 (for step 207, seeFIG. 12).

Step 401: the recording control section 120 references positionalinformation stored in the management information position memory 164 toincrementally write the management information 8 stored in theinformation storing buffer 140 to the management information area 7.

Step 402: based on the incrementally written area, positionalinformation stored in the management information position memory 164 ischanged to information indicating the incrementally writable position ofthe management information area 7. Thereafter, the process is ended.

FIG. 15 shows a procedure for adding a recording area in detail.

Hereinafter, a procedure for adding a recording area will be describedstep by step in detail with reference to FIGS. 11 and 15 (for step 203,see FIG. 12).

Step 501: it is determined whether or not there is a space in the entrynumber array 10 and the recording area entry 11 (i.e., whether or notthere is a field having a value of “0” in the fields of the entry numberarray 10 and the fields of the recording area entry 11, or whether ornot the number of fields already used of the fields of the entry numberarray 10 and the fields of the recording area entry 11 is less than themaximum number).

When it is determined that there is a space, the process goes to step502, in which the entry number array 10 having a space or an entrynumber #m corresponding to a recording area in the recording area entry11 is used. When it is determined that there is not a space, the processgoes to step 503.

Step 502: it is determined whether or not an area having a size equal toor greater than a size (S) requested by a higher-level control apparatusarea can be secured (i.e., the size of an area from an incrementallywritable position to the end of the data area 5 is greater than S) Notethat an incrementally writable position can be obtained based on thestart position 13 and the last recorded position 14 of a recording area#(m−1).

When it is determined that a sufficient area can be secured, the processgoes to step 504. When it is not determined that a sufficient area canbe secured, the process goes to step 503.

Step 503: information indicating the contents of an error is sent to thehigher-level control apparatus, and the process is ended.

Step 504: a value obtained by adding the size S to the incrementallywritable position of the recording area #(m−1) is set to be the startposition 13 of the recording area entry #m, and the process goes to step505.

For example, when no recording area #(m−1) has been recorded (the lastrecorded position 14 is 0), a value obtained by adding the size S to thestart position 13 of the recording area #(m−1) is set to be the startposition 13 of the recording area #m.

Step 505: the value m is added to the entry number array 10, and theprocess is ended.

FIG. 16 shows a procedure for closing a recording area.

Hereinafter, a procedure for closing a recording area will be describedstep by step in detail with reference to FIGS. 11 and 16 (for step 205,see FIG. 12).

Step 601: it is determined whether or not a recording area entry number(TRACK number) designated by a higher-level control apparatuscorresponds to a recording area entry number contained in the entrynumber array 10.

When the determination is affirmative, the process goes to step 602, inwhich the entry number #m of the recording area is used. When thedetermination is not affirmative, the process goes to step 603.

Step 602: it is determined whether or not the recording area #m is anoutermost recording area. For example, when the start position 13 of therecording area entry #(m+1) is 0, it can be determined that therecording area #m is an outermost recording area.

When it is determined that the recording area #m is an outermostrecording area (Yes), the process goes to step 604. When it isdetermined that the recording area #m is not an outermost recording area(No), the process goes to the step 606.

Step 603: information indicating the contents of error is sent to thehigher-level control apparatus, and the process is ended.

Step 604: the start position 13 of the recording area entry #(m+1) isset to be an incrementally writable position, and the process goes tostep 605. The incrementally writable position is obtained from the startposition 13 and the last recorded position 14 of the recording areaentry #m (portions (k) of FIGS. 5 and 6).

Step 605: the value (m+1) is added to the entry number array 10, and theprocess goes to step 607.

Step 606: 0-padding data is recorded into an area from the incrementallywritable position to the start position 13 of the recording area entry#(m+1), and the process goes to step 607.

Note that in this step, recording data may not be necessarily 0-paddingdata. This step itself may be omitted.

Step 607: the value m is changed to a value of 0 in the entry numberarray 10.

FIG. 17 shows details of a procedure for closing a session.

Hereinafter, a procedure for closing a session will be described step bystep in detail with reference to FIGS. 11 and 17 (for step 206, see FIG.12).

Step 701: it is determined whether or not only a single value indicatingan outermost recording area is registered in the entry number array 10.

When the determination is affirmative (Yes), the process goes to step702. When the determination is not affirmative (No), the process goes tostep 703.

Generally, in a write-once recording medium, such as CD-R or DVD-R,TRACK needs to have been closed in order to close SESSION. For example,the condition is satisfied when all recording areas excluding anoutermost recording area which is an unrecorded area are in thenon-incrementally writable state (see portion (f) of FIG. 4 and portion(k) of FIG. 6). In step 701, it is determined whether or not theabove-described condition is satisfied.

Step 702: it is determined whether or not the last recorded position 14of an outermost recording area entry has a value of “0”.

When the determination is affirmative (Yes), the process goes to step704. When the determination is not affirmative (No), the process goes tostep 703.

Step 703: information indicating the contents of error is sent to thehigher-level control apparatus, and the process is ended.

Step 704: the value of the session start flag 12 given to an outermostrecording area entry is set to be a value of “1”, and the process isended.

Note that step 702 of the session closing procedure (steps 701 to 704)is an example in which when a boundary of a session is newly added, itis determined whether or not a recording area containing a sector havinga maximum sector number of at least one recording area has already beenrecorded.

According to the recording method and the recording apparatus of thepresent invention, it is possible to record management information ontothe write-once recording medium of the present invention. Sincemanagement information can be recorded onto the write-once recordingmedium having only a small size of area for recording managementinformation, the time required for searching for the latest managementinformation can be reduced. As a result, the time required from when theuser loads the write-once recording medium into an apparatus to when auser data area of the write-once recording medium is ready to access,can be reduced.

A recording method according to an embodiment of the present inventionhas heretofore been described with reference to FIGS. 12 to 17.

For example, in the embodiment of FIG. 12, step 203, step 205, step 206and step 208 correspond to the “step of generating managementinformation containing range information indicating a recording range ofat least one recording area and identification information foridentifying a recording area located at a boundary of a session” andstep 207 corresponds to the “step of recording the resultant managementinformation into a management information area”.

However, the recording method of the present invention is not limited tothe embodiment of FIG. 12. The recording method of the present inventionmay be achieved by any arbitrary procedure as long as the procedure hasfunctions of the “step of generating management information containingrange information indicating a recording range of at least one recordingarea and identification information for identifying a recording arealocated at a boundary of a session” and the “step of recording theresultant management information into a management information area”.

For example, when management information 8 containing a session toggleflag is recorded onto a write-once recording medium (FIGS. 7 and 8), thestep of causing the session toggle flag 15 of a recording areaimmediately before the recording area #m (i.e., a recording area #(m−1))to have the same value as that of the session toggle flag 15 isperformed in conjunction with the step of adding a recording area (step504 in FIG. 15). In addition, the step of inverting the session toggleflag 15 of the recording area #m with respect to that of the recordingarea #(m−1) is performed instead of the step of closing a session (step704 in FIG. 17).

For example, when management information 8 containing an entry numberarray of a recording area at the beginning of a session is recorded ontoa write-once recording medium (FIGS. 9 and 10), the step of registeringthe entry number of an outermost recording area into the entry numberarray 16 is performed instead of the step of closing a session (step 704in FIG. 17).

3-1. Reproduction Apparatus

Hereinafter, a reproduction apparatus according to an embodiment of thepresent invention will be described with reference to the accompanyingdrawings.

FIG. 18 shows an exemplary structure of an optical disc apparatus 200according to an embodiment of the present invention.

The optical disc apparatus 200 serves as a reproduction apparatusaccording to an embodiment of the present invention, when reproducinginformation.

The optical disc apparatus 200 is connected to an I/O bus 270. The I/Obus 270 is connected to a higher-level control apparatus (not shown).The higher-level control apparatus is typically a host computer.

The optical disc apparatus 200 is configured to load an optical disc 1thereinto. The optical disc apparatus 200 comprises a command processingsection 210 for processing a command from a higher-level controlapparatus, a reproduction control section 230 for controllingreproduction of the optical disc 1, a management information storingbuffer 240 for storing management information 8 (FIG. 1), a data buffer250 for temporarily storing reproduced data, and a recording managementprocessing section 260 for processing management information 8.

The recording management processing section 26Q comprises a managementinformation reading section 261 and a management-information recognizingsection 265.

The management information reading section 261 searches for lastrecorded management information 8 among at least one piece of managementinformation 8 recorded in a management information area 7, and outputsthe management information 8 last recorded in the management informationarea 7 into a management information storing buffer 240.

The management information recognizing section 265 generates data basedthe contents of the management information storing buffer 240 inresponse to a command from a higher-level control apparatus and outputsthe data to the higher-level control apparatus.

3-2. Reproduction Method

FIG. 19 shows a reproduction procedure according to an embodiment of thepresent invention.

Hereinafter, a reproduction procedure according to an embodiment of thepresent invention will be described step by step with reference to FIGS.18 and 19.

Step 1201: when the optical disc 1 is loaded in the optical discapparatus, 200, the management information reading section 261 reads outthe latest management information 8, and stores the latest managementinformation 8 into the management information storing buffer 240.

Step 1202: the optical disc apparatus 200 is ready to receive commandsrelating to the optical disc 1 from a higher-level control apparatusuntil the optical disc 1 is ejected or the power source is turned off.

When a READ DISC INFORMATION command is issued to the optical disc 1,the process goes to step 1203. When a READ TRACK INFORMATION command isissued to the optical disc 1, the process goes to step 1206. When othercommands are issued to the optical disc 1, the process goes to step1210.

The READ DISC INFORMATION command is a command from a higher-levelcontrol apparatus, which requests a report of disc information. The READTRACK INFORMATION command is a command from a higher-level controlapparatus, which requests a report of track information.

Step 1203: the total number of sessions is calculated (determined) basedon the management information 8 read out.

Step 1204: a recording area which is located at the beginning of thelast session, is determined (calculated).

Step 1205: other information (for example, a leading recording area onthe optical disc 1 (consistently the number “1”), the last recordingarea in the last session (i.e., the last recording area of the opticaldisc 1), etc.) is obtained. Thereafter, the process goes to step 1211.

Step 1206: when the READ TRACK INFORMATION command is received from ahigher-level control apparatus, it is determined whether or not TRACK isdesignated (a recording area is designated).

If the determination is affirmative (Yes), the process goes to step1208. If the determination is not affirmative (No), the process goes tostep 1207.

Step 1207: a recording area to which the designated logic sector numberbelongs is determined.

Step 1208: a session to which a predetermined recording area (thedesignated recording area or a recording area to which the designatedlogic sector number belongs) is determined (calculated).

Step 1209: other information (for example, the start position of arecording area (corresponding to the start position 13), the lastposition of user data (corresponding to the last recorded position 14),the number of free blocks, etc.) is determined, and the process goes tostep 1211. Note that the number of free blocks can be calculated by thefour fundamental operations of arithmetic based on at least one of thestart position 13 and the last recorded position 14.

Step 1210: when other commands are received from a higher-level controlapparatus, processing is performed in accordance with the contents ofthe command, the process goes to step 1211.

Step 1211: data is transferred to a higher-level control apparatus.

FIG. 20 shows an exemplary calculation procedure according to anembodiment of the present invention.

The calculation procedure is performed by the management informationrecognizing section 265 based on management information 8 containing asession start flag (FIGS. 2 to 6). The calculation procedure calculatesthe total number of sessions (step 1203 in FIG. 19) and determines arecording area located at the beginning of a last session (step 1204 inFIG. 19), and determines a session to which a predetermined recordingarea belongs (step 1208 in FIG. 19).

Note that in the calculation of the total number of sessions (step 1203in FIG. 19) and the determination of a recording area located at thebeginning of a last session (step 1204 in FIG. 19), the total number ofrecording areas is designated as Tspec. In the determination of asession to which a predetermined recording area belongs (step 1208 inFIG. 19), the number of a desired recording area is designated as Tspec.

Hereinafter, an exemplary calculation procedure according to anembodiment of the present invention will be described step by step withreference to FIG. 20.

Step 1301: the number T of a recording area is initialized to a number“1”, and the number S of a session is initialized to a number “0”.

Step 1302: it is determined whether or not the number T of a recordingarea is equal to or smaller than the number Tspec of the designatedrecording area.

If the determination is affirmative (Yes), the process goes to step1303. If the determination is not affirmative (No), the process isended.

Step 1303: the value of the session start flag 12 given to the recordingarea #T is substituted into F (F=the value of the session start flag 12given to the recording area #T).

Step 1304: it is determined whether or not the value of F is equal to avalue of “1”.

If the determination is affirmative, the process goes to step 1305. Ifthe determination is not affirmative, the process goes to step 1307.

Step 1305: “1” is added to the session number S. Thereafter, the processgoes to step 1306.

Step 1306: T is substituted into Tfirst (the number of a recording arealocated at the beginning of a session).

Step 1307: 1 is added to the recording area number T to proceed into thenext recording area.

If the total number of recording areas is substituted into Tspec, thetotal number of sessions is stored into S, and the number of a recordingarea located at a last session is stored into Tfirst.

If the number of a desired recording area is substituted into Tspec, thenumber of a session to which the recording area belongs is stored intoS, and the number of a recording area located at the beginning of thesession is stored into Tfirst.

FIG. 21 shows another exemplary calculation procedure according to anembodiment of the present invention.

The calculation procedure is performed by the management informationrecognizing section 265 based on management information 8 containing asession toggle flag (FIGS. 7 and 8). The calculation procedurecalculates the total number of sessions (Step 1203 in FIG. 19),determines a recording area located at the beginning of a last session(Step 1204 in FIG. 19), and determines a session to which apredetermined recording area belongs (Step 1208 in FIG. 19).

A method for designating Tspec, and the meanings of S after calculationand Tfirst, are similar to those which are described with reference toFIG. 20. In FIG. 21, the same step as that in FIG. 20 is referenced withthe same reference numeral, and its description is omitted.

Hereinafter, another exemplary calculation procedure according to anembodiment of the present invention will be described step by step withreference to FIG. 21.

Step 1401: before performing step 1302, the previous flag value Fpre isinitialized to a value of “0”.

Step 1402: instead of performing step 1304 (FIG. 20), it is determinedwhether or not the current flag value F is inverse to the previous flagvalue Fpre.

If the determination is affirmative (Yes), the process goes to step1305. If the determination is not affirmative (No), the process goes tostep 1403.

Step 1403: before proceeding to the next recording area (step 1307), theprevious flag value Fpre is set to be the current flag value F (Fpre=F).

FIG. 22 shows still another exemplary calculation procedure according toan embodiment of the present invention.

The calculation procedure is performed by the management informationrecognizing section 265 based on management information 8 containing anentry number array of recording areas located at sessions (FIGS. 9 and10). The calculation procedure calculates the total number of sessions(step 1203 in FIG. 19), determines a recording area located at thebeginning of a last session (Step 1204 in FIG. 19), and determines asession to which a predetermined recording area belongs (step 1208 inFIG. 19).

A method for designating Tspec, and the meanings of S after calculationand Tfirst, are similar to those which are described with reference toFIG. 20.

Hereinafter, still another exemplary calculation procedure according toan embodiment of the present invention will be described step by stepwith reference to FIG. 22.

Step 1501: the session number S is initialized to a number “1”.

Step 1502: Tfirst is initialized to the number of a recording arealocated at the beginning of the session #S.

Step 1503: Tnext is set to be the number of a recording area located atthe next session #(S+1).

Step 1504: it is determined whether or not Tnext exists.

If the determination is affirmative (Yes: Tnext≠0), the process goes tostep 1505. If the determination is not affirmative (No: Tnext=0), theprocess is ended.

Step 1505: it is determined whether or not Tnext is equal to or smallerthan the designated recording area number Tspec.

If the determination is affirmative (Yes), the process goes to step1506. If the determination is not affirmative (No), the process isended.

Step 1506: Tfirst is set to be Tnext.

Step 1507: 1 is added to the session number S to proceed the nextsession.

Thus, according to the reproduction method and the reproductionapparatus of the present invention, management information can bereproduced from the write-once recording medium of the presentinvention. The size of an area for reproducing management information issmall in the write-once recording medium of the present invention.Therefore, it is possible to reduce the time required for searching forthe latest management information. As a result, it is possible to reducethe time spent from when the user loads the write-once recording mediuminto an apparatus to when a user data area of the write-once recordingmedium becomes accessible.

The reproduction method of the embodiment of the present invention hasbeen heretofore described with reference to FIGS. 19 to 22.

For example, in the embodiment of FIG. 19, step 1201 corresponds to the“step of reading out management information from a managementinformation area”, and steps 1203, 1204 and 1208 correspond to the “stepof recognizing information regarding a session based on the managementinformation read out”.

However, the reproduction method of the present invention is not limitedto the embodiment of FIG. 19. The reproduction method of the presentinvention may be achieved by any arbitrary procedure as long as theprocedure has functions of the “step of reading out managementinformation from a management information area” and the “step ofrecognizing information regarding a session based on the managementinformation read out”.

Embodiments of the present invention will be described with reference toFIGS. 1 to 22.

The layout of areas in the write-once recording medium of theembodiments of the present invention is provided as an example. In theembodiments, the management information area 7 is provided in thelead-in area 4. The present invention is not limited to this. Themanagement information area 7 may be provided in an area other than thelead-in area 4. For example, the management information area 7 isprovided may be provided in the lead-out area 6 or the data area 5.

In the above-described embodiments of the present invention, the orderof reading information from areas is provided as an example. Forexample, management information 8 is incrementally written into amanagement information area 7 of the optical disc 1 from its innerperiphery to its outer periphery. The present invention is not limitedto this. Management information 8 may be incrementally written into amanagement information area 7 of the optical disc 1 from its outerperiphery to its inner periphery.

Although certain preferred embodiments have been described herein, it isnot intended that such embodiments be construed as limitations on thescope of the invention except as set forth in the appended claims.Various other modifications and equivalents will be apparent to and canbe readily made by those skilled in the art, after reading thedescription herein, without departing from the scope and spirit of thisinvention. All patents, published patent applications and publicationscited herein are incorporated by reference as if set forth fully herein.

For a large-capacity optical disc capable of recording/reproductionusing short-wavelength laser (e.g., blue laser) and an apparatus capableof recording/reproduction of the optical disc, a reduction in the sizeof management information is useful in terms of the available capacityof an optical disc and the memory capacity of an apparatus.

The present invention can be applied to not only a write-once recordingmedium but also, for example, a rewritable recording medium which isvirtually used as a write-once recording medium.

1. A write-once recording medium, comprising: a management informationarea for recording management information for managing a recorded state;and a user data area for recording user data, wherein the user data areais configured to contain at least one recording area, at least onesession is configured to contain at least one of the at least onerecording area, the management information contains, for each saidrecording area, range information indicating a recording range of thatrecording area and identification information for identifying whether ornot that recording area is located at a boundary of the session, theidentification information is a flag provided to each said recordingarea, and the flag has either a value of “0” or a value of “1”.
 2. Arecording apparatus for a write-once recording medium, wherein themedium comprises: a management information area for recording managementinformation for managing a recorded state; and a user data area forrecording user data, wherein the user data area is configured to containat least one recording area, at least one session is configured tocontain at least one of the at least one recording area, the managementinformation contains, for each said recording area, range informationindicating a recording range of that recording area and identificationinformation for identifying whether or not that recording area islocated at a boundary of the session, the identification information isa flag provided to each said recording area, and the flag has either avalue of “0” or a value of “1” the apparatus comprising: (a) a sectionfor generating the management information; and (b) a section forrecording the management information into the management informationarea.
 3. A reproduction apparatus for a write-once recording medium,wherein the medium comprises: a management information area forrecording management information for managing a recorded state; and auser data area for recording user data, wherein the user data area isconfigured to contain at least one recording area, at least one sessionis configured to contain at least one of the at least one recordingarea, the management information contains, for each said recording area,range information indicating a recording range of that recording areaand identification information for identifying whether or not thatrecording area is located at a boundary of the session, theidentification information is a flag provided to each said recordingarea, and the flag has either a value of “0” or a value of “1” theapparatus comprises: (a) a section for reading out the managementinformation from the management information area; and (b) a section forrecognizing information regarding the at least one session based on themanagement information read out.